Use constexpr TaskTraits constructor in chrome.

chrome/browser/chromeos/system_logs/touch_log_source_ozone.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/system_logs/touch_log_source.h"
 
 #include <stddef.h>
 
 #include "ash/touch/touch_hud_debug.h"
 #include "base/bind.h"
@@ skipping 108 matching lines @@
 
   // For now only touchpad (and mouse) logs are actually collected.
   for (size_t i = 0; i < commands.size(); ++i) {
     std::string output;
     base::GetAppOutput(commands[i].second, &output);
     (*response)[commands[i].first] = output;
   }
 
   // Cleanup these temporary log files.
   base::PostTaskWithTraits(
-      FROM_HERE,
-      base::TaskTraits().MayBlock().WithPriority(
-          base::TaskPriority::BACKGROUND),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::Bind(CleanupEventLog, base::Passed(&log_paths)));
 }
 
 // Callback for handing the outcome of GetTouchEventLog().
 //
 // This is the end of the whole touch log collection process.
 void OnEventLogCollected(
     std::unique_ptr<system_logs::SystemLogsResponse> response,
     const system_logs::SysLogsSourceCallback& callback,
     std::unique_ptr<std::vector<base::FilePath>> log_paths) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   // We cannot eliminate these temporaries and inline these closures because the
   // compiler may call release() before get().
   const base::Closure pack_closure =
       base::Bind(&PackEventLog, base::Unretained(response.get()),
                  base::Passed(&log_paths));
   const base::Closure callback_closure =
       base::Bind(callback, base::Owned(response.release()));
-  base::PostTaskWithTraitsAndReply(FROM_HERE,
-                                   base::TaskTraits().MayBlock().WithPriority(
-                                       base::TaskPriority::BACKGROUND),
-                                   pack_closure, callback_closure);
+  base::PostTaskWithTraitsAndReply(
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
+      pack_closure, callback_closure);
 }
 
 // Callback for handing the outcome of GetTouchDeviceStatus().
 //
 // Appends the collected log to the SystemLogsResponse map. Also goes on to
 // collect touch event logs.
 void OnStatusLogCollected(
     std::unique_ptr<system_logs::SystemLogsResponse> response,
     const system_logs::SysLogsSourceCallback& callback,
     std::unique_ptr<std::string> log) {
@@ skipping 30 matching lines @@
 
   std::unique_ptr<SystemLogsResponse> response(new SystemLogsResponse);
   CollectTouchHudDebugLog(response.get());
 
   // Collect touch device status logs.
   ui::OzonePlatform::GetInstance()->GetInputController()->GetTouchDeviceStatus(
       base::Bind(&OnStatusLogCollected, base::Passed(&response), callback));
 }
 
 }  // namespace system_logs